WASHINGTON -- Sen. Harry Reid, the tough tactician who has led Senate Democrats since 2005, will not seek re-election next year, bringing an end to a three-decade congressional career that culminated with his push of President Barack Obama's ambitious agenda against fierce Republican resistance.
Reid, 75, who suffered serious eye and facial injuries in a Jan. 1 exercise accident at his Las Vegas home, said he had been contemplating retiring from the Senate for months. He said his decision was not attributable either to the accident or to his demotion to minority leader after Democrats lost the majority in November's midterm elections.
"I understand this place," Reid said. "I have quite a bit of power as minority leader."
He has already confounded the new Republican majority this year by holding Democrats united against a proposal to gut the Obama administration's immigration policies as well as a human-trafficking measure Democrats objected to over an anti-abortion provision.
"I want to be able to go out at the top of my game," said Reid, who used a sports metaphor about athletes who try to hang on too long. "I don't want to be a 42-year-old trying to become a designated hitter."
Reid's tenure has become increasingly combative in recent years and included a procedural change on nominations that infuriated Republicans. He also came under fire for blocking floor debate, and even some of his Democratic colleagues suggested that he was stifling the Senate. Just this week, he alienated House Democrats who thought he was sabotaging a compromise on Medicare.
His departure at the end of 2016 will create an opening both at the top of the Senate Democratic hierarchy and in a Senate contest that would have been a megaspending slugfest in the presidential battleground of Nevada. Conservatives such as Charles G. and David H. Koch, the billionaire brothers who were a favorite target of Reid criticism in 2014, would have spared no expense in trying to oust him.
Sen. Charles E. Schumer of New York, who helped Democrats capture the Senate in 2006 and has led their political messaging operation, is considered the favorite to succeed Reid as party leader. Sen. Richard J. Durbin of Illinois, the Senate's No. 2 Democrat, could also be a contender for the job, but it is unclear how strongly he would pursue it.
In Nevada, Catherine Cortez Masto, the state's former attorney general, is considered a strong Democratic candidate with Reid out; the Republican field will be fluid and is likely to include Michael Roberson, a State Senate leader.
Reid had previously insisted he was running and said he was confident that he could have triumphed next year had he decided to seek a sixth term. The onetime amateur boxer noted he might not have even run in 2010 if Republicans had not made such a point of trying to unseat him.
He also said he was worried his race would consume campaign money that would be needed in other competitive states as Democrats try to regain control of the Senate.
"I think it is unfair for me to be soaking up all the money to be re-elected with what we are doing in Maryland, in Pennsylvania, in Missouri, in Florida," he said. "These are big, expensive states."
First elected to the House in 1982, the former trial lawyer and head of the Nevada gaming commission won his Senate seat in 1986 and joined the leadership about a decade later. Reid took over the top job in 2005 after Tom Daschle, then the leader, lost his re-election bid.
After a tough election night in 2004, some other top Democrats suggested they might want to consider a leadership bid, but Reid had the election sewn up by the next day. He is the longest-serving member of Congress from Nevada, and the second-longest-serving Democratic leader after Mike Mansfield of Montana.
Like his chief adversary, Sen. Mitch McConnell, R-Ky., Reid learned the workings of the Senate in the trenches as the vote-counting whip and takes pride in his floor expertise.
Unhappy with the slow pace of judicial and executive branch confirmations, Reid engineered a change in Senate procedure in 2013 that allowed Democrats to overcome filibusters against nominees with a simple majority. The change led to a flurry of new judges being named to important appeals courts, though Republicans accused him of changing the nature of the Senate and running roughshod over the minority.
After the election of Obama and Democratic gains in 2008, Reid did the deal-making and vote counting required to push through the new health care law with no Republican votes and the economic stimulus with just a handful.
"I am so happy that we were able to get the health care bill passed," he said, acknowledging that there were times he wondered why he did not give up. "Like a fool, I kept coming back."
After opposing a more forgiving immigration policy earlier in his career, Reid became a champion of granting legal status to immigrants living in the country illegally, an evolution he attributes to his relationship with his state's growing Hispanic population. He was crucial to Senate passage of bipartisan, comprehensive immigration legislation in 2013 - a bill the House did not take up - and said the advocates for the immigrants would ultimately prevail.
"We have won that debate," said Reid, who has also made pushing for expanded use of alternative energy a legislative priority.
His strict management of the Senate the past few years became an issue in the 2014 elections as Republicans accused him of stifling debate and denying even Democrats an opportunity to push their priorities on the Senate floor. He blamed Republicans for the legislative gridlock, citing their deep opposition to Obama and their determination to deny him any victories.
Reid said he believed the Supreme Court decision in the Citizens United case that allowed a flood of money from super-rich Americans into politics had been a disaster for Congress, even as he acknowledged that he had to adopt some of the same tactics himself to keep Democrats competitive. His push for reining in unlimited spending is likely to be a priority for him in his remaining months.
Reid said he had seen one important change for the better in the Senate: an influx of female senators.
"This place is so much better because of women," he said. "Men and women are different, and they have changed the dynamic of the Senate."